
/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
#include "SampleCode.h"
#include "SkView.h"
#include "SkCanvas.h"
#include "SkGradientShader.h"
#include "SkGraphics.h"
#include "SkImageDecoder.h"
#include "SkPath.h"
#include "SkRandom.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkUtils.h"
#include "SkXfermode.h"
#include "SkColorPriv.h"
#include "SkColorFilter.h"
#include "SkTime.h"
#include "SkTypeface.h"

#include "SkOSFile.h"
#include "SkStream.h"

#include "SkGeometry.h" // private include :(

static void drawtriangle(SkCanvas* canvas, const SkPaint& paint,
                         const SkPoint pts[3])
    {
    SkPath path;

    path.moveTo(pts[0]);
    path.lineTo(pts[1]);
    path.lineTo(pts[2]);

    canvas->drawPath(path, paint);
    }

static SkShader* make_shader0(SkIPoint* size)
    {
    SkBitmap    bm;

//    SkImageDecoder::DecodeFile("/skimages/progressivejpg.jpg", &bm);
    SkImageDecoder::DecodeFile("/skimages/logo.png", &bm);
    size->set(bm.width(), bm.height());
    return SkShader::CreateBitmapShader(bm, SkShader::kClamp_TileMode,
                                        SkShader::kClamp_TileMode);
    }

static SkShader* make_shader1(const SkIPoint& size)
    {
    SkPoint pts[] = { { 0, 0, },
            { SkIntToScalar(size.fX), SkIntToScalar(size.fY) }
        };
    SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE, SK_ColorRED };
    return SkGradientShader::CreateLinear(pts, colors, NULL,
                                          SK_ARRAY_COUNT(colors), SkShader::kMirror_TileMode, NULL);
    }

///////////////////////////////////////////////////////////////////////////////

class Patch
    {
    public:
        Patch()
            {
            sk_bzero(fPts, sizeof(fPts));
            }
        ~Patch() {}

        void setPatch(const SkPoint pts[12])
            {
            memcpy(fPts, pts, 12 * sizeof(SkPoint));
            fPts[12] = pts[0];  // the last shall be first
            }
        void setBounds(int w, int h)
            {
            fW = w;
            fH = h;
            }

        void draw(SkCanvas*, const SkPaint&, int segsU, int segsV,
                  bool doTextures, bool doColors);

    private:
        SkPoint fPts[13];
        int     fW, fH;
    };

static void eval_patch_edge(const SkPoint cubic[], SkPoint samples[], int segs)
    {
    SkScalar t = 0;
    SkScalar dt = SK_Scalar1 / segs;

    samples[0] = cubic[0];
    for (int i = 1; i < segs; i++)
        {
        t += dt;
        SkEvalCubicAt(cubic, t, &samples[i], NULL, NULL);
        }
    }

static void eval_sheet(const SkPoint edge[], int nu, int nv, int iu, int iv,
                       SkPoint* pt)
    {
    const int TL = 0;
    const int TR = nu;
    const int BR = TR + nv;
    const int BL = BR + nu;

    SkScalar u = SkIntToScalar(iu) / nu;
    SkScalar v = SkIntToScalar(iv) / nv;

    SkScalar uv = SkScalarMul(u, v);
    SkScalar Uv = SkScalarMul(SK_Scalar1 - u, v);
    SkScalar uV = SkScalarMul(u, SK_Scalar1 - v);
    SkScalar UV = SkScalarMul(SK_Scalar1 - u, SK_Scalar1 - v);

    SkScalar x0 = SkScalarMul(UV, edge[TL].fX) + SkScalarMul(uV, edge[TR].fX) +
                  SkScalarMul(Uv, edge[BL].fX) + SkScalarMul(uv, edge[BR].fX);
    SkScalar y0 = SkScalarMul(UV, edge[TL].fY) + SkScalarMul(uV, edge[TR].fY) +
                  SkScalarMul(Uv, edge[BL].fY) + SkScalarMul(uv, edge[BR].fY);

    SkScalar x =    SkScalarMul(SK_Scalar1 - v, edge[TL+iu].fX) +
                    SkScalarMul(u, edge[TR+iv].fX) +
                    SkScalarMul(v, edge[BR+nu-iu].fX) +
                    SkScalarMul(SK_Scalar1 - u, edge[BL+nv-iv].fX) - x0;
    SkScalar y =    SkScalarMul(SK_Scalar1 - v, edge[TL+iu].fY) +
                    SkScalarMul(u, edge[TR+iv].fY) +
                    SkScalarMul(v, edge[BR+nu-iu].fY) +
                    SkScalarMul(SK_Scalar1 - u, edge[BL+nv-iv].fY) - y0;
    pt->set(x, y);
    }

static int ScalarTo255(SkScalar v)
    {
    int scale = SkScalarToFixed(v) >> 8;
    if (scale < 0)
        {
        scale = 0;
        }
    else if (scale > 255)
        {
        scale = 255;
        }
    return scale;
    }

static SkColor make_color(SkScalar s, SkScalar t)
    {
    int cs = ScalarTo255(s);
    int ct = ScalarTo255(t);
    return SkColorSetARGB(0xFF, cs, 0, 0) + SkColorSetARGB(0, 0, ct, 0);
    }

void Patch::draw(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
                 bool doTextures, bool doColors)
    {
    if (nu < 1 || nv < 1)
        {
        return;
        }

    int i, npts = (nu + nv) * 2;
    SkAutoSTMalloc<16, SkPoint> storage(npts + 1);
    SkPoint* edge0 = storage.get();
    SkPoint* edge1 = edge0 + nu;
    SkPoint* edge2 = edge1 + nv;
    SkPoint* edge3 = edge2 + nu;

    // evaluate the edge points
    eval_patch_edge(fPts + 0, edge0, nu);
    eval_patch_edge(fPts + 3, edge1, nv);
    eval_patch_edge(fPts + 6, edge2, nu);
    eval_patch_edge(fPts + 9, edge3, nv);
    edge3[nv] = edge0[0];   // the last shall be first

    for (i = 0; i < npts; i++)
        {
//        canvas->drawLine(edge0[i].fX, edge0[i].fY, edge0[i+1].fX, edge0[i+1].fY, paint);
        }

    int row, vertCount = (nu + 1) * (nv + 1);
    SkAutoTMalloc<SkPoint>  vertStorage(vertCount);
    SkPoint* verts = vertStorage.get();

    // first row
    memcpy(verts, edge0, (nu + 1) * sizeof(SkPoint));
    // rows
    SkPoint* r = verts;
    for (row = 1; row < nv; row++)
        {
        r += nu + 1;
        r[0] = edge3[nv - row];
        for (int col = 1; col < nu; col++)
            {
            eval_sheet(edge0, nu, nv, col, row, &r[col]);
            }
        r[nu] = edge1[row];
        }
    // last row
    SkPoint* last = verts + nv * (nu + 1);
    for (i = 0; i <= nu; i++)
        {
        last[i] = edge2[nu - i];
        }

//    canvas->drawPoints(verts, vertCount, paint);

    int stripCount = (nu + 1) * 2;
    SkAutoTMalloc<SkPoint>  stripStorage(stripCount * 2);
    SkAutoTMalloc<SkColor>  colorStorage(stripCount);
    SkPoint* strip = stripStorage.get();
    SkPoint* tex = strip + stripCount;
    SkColor* colors = colorStorage.get();
    SkScalar t = 0;
    const SkScalar ds = SK_Scalar1 * fW / nu;
    const SkScalar dt = SK_Scalar1 * fH / nv;
    r = verts;
    for (row = 0; row < nv; row++)
        {
        SkPoint* upper = r;
        SkPoint* lower = r + nu + 1;
        r = lower;
        SkScalar s = 0;
        for (i = 0; i <= nu; i++)
            {
            strip[i*2 + 0] = *upper++;
            strip[i*2 + 1] = *lower++;
            tex[i*2 + 0].set(s, t);
            tex[i*2 + 1].set(s, t + dt);
            colors[i*2 + 0] = make_color(s/fW, t/fH);
            colors[i*2 + 1] = make_color(s/fW, (t + dt)/fH);
            s += ds;
            }
        t += dt;
        canvas->drawVertices(SkCanvas::kTriangleStrip_VertexMode, stripCount,
                             strip, doTextures ? tex : NULL,
                             doColors ? colors : NULL, NULL,
                             NULL, 0, paint);
        }
    }

static void drawpatches(SkCanvas* canvas, const SkPaint& paint, int nu, int nv,
                        Patch* patch)
    {

    SkAutoCanvasRestore ar(canvas, true);

    patch->draw(canvas, paint, 10, 10, false, false);
    canvas->translate(SkIntToScalar(180), 0);
    patch->draw(canvas, paint, 10, 10, true, false);
    canvas->translate(SkIntToScalar(180), 0);
    patch->draw(canvas, paint, 10, 10, false, true);
    canvas->translate(SkIntToScalar(180), 0);
    patch->draw(canvas, paint, 10, 10, true, true);
    }

class PatchView : public SampleView
    {
        SkShader*   fShader0;
        SkShader*   fShader1;
        SkIPoint    fSize0, fSize1;
        SkPoint     fPts[12];

    public:
        PatchView()
            {
            fShader0 = make_shader0(&fSize0);
            fSize1 = fSize0;
            if (fSize0.fX == 0 || fSize0.fY == 0)
                {
                fSize1.set(2, 2);
                }
            fShader1 = make_shader1(fSize1);

            const SkScalar S = SkIntToScalar(50);
            const SkScalar T = SkIntToScalar(40);
            fPts[0].set(S*0, T);
            fPts[1].set(S*1, T);
            fPts[2].set(S*2, T);
            fPts[3].set(S*3, T);
            fPts[4].set(S*3, T*2);
            fPts[5].set(S*3, T*3);
            fPts[6].set(S*3, T*4);
            fPts[7].set(S*2, T*4);
            fPts[8].set(S*1, T*4);
            fPts[9].set(S*0, T*4);
            fPts[10].set(S*0, T*3);
            fPts[11].set(S*0, T*2);

            this->setBGColor(SK_ColorGRAY);
            }

        virtual ~PatchView()
            {
            SkSafeUnref(fShader0);
            SkSafeUnref(fShader1);
            }

    protected:
        // overrides from SkEventSink
        virtual bool onQuery(SkEvent* evt)
            {
            if (SampleCode::TitleQ(*evt))
                {
                SkString str("Patch");
                SampleCode::TitleR(evt, str.c_str());
                return true;
                }
            return this->INHERITED::onQuery(evt);
            }

        virtual void onDrawContent(SkCanvas* canvas)
            {
            SkPaint paint;
            paint.setDither(true);
            paint.setFilterBitmap(true);

            canvas->translate(SkIntToScalar(20), 0);

            Patch   patch;

            paint.setShader(fShader0);
            if (fSize0.fX == 0)
                {
                fSize0.fX = 1;
                }
            if (fSize0.fY == 0)
                {
                fSize0.fY = 1;
                }
            patch.setBounds(fSize0.fX, fSize0.fY);

            patch.setPatch(fPts);
            drawpatches(canvas, paint, 10, 10, &patch);

            paint.setShader(NULL);
            paint.setAntiAlias(true);
            paint.setStrokeWidth(SkIntToScalar(5));
            canvas->drawPoints(SkCanvas::kPoints_PointMode, SK_ARRAY_COUNT(fPts), fPts, paint);

            canvas->translate(0, SkIntToScalar(300));

            paint.setAntiAlias(false);
            paint.setShader(fShader1);
            patch.setBounds(fSize1.fX, fSize1.fY);
            drawpatches(canvas, paint, 10, 10, &patch);
            }

        class PtClick : public Click
            {
            public:
                int fIndex;
                PtClick(SkView* view, int index) : Click(view), fIndex(index) {}
            };

        static bool hittest(const SkPoint& pt, SkScalar x, SkScalar y)
            {
            return SkPoint::Length(pt.fX - x, pt.fY - y) < SkIntToScalar(5);
            }

        virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y)
            {
            for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); i++)
                {
                if (hittest(fPts[i], x, y))
                    {
                    return new PtClick(this, i);
                    }
                }
            return this->INHERITED::onFindClickHandler(x, y);
            }

        virtual bool onClick(Click* click)
            {
            fPts[((PtClick*)click)->fIndex].set(click->fCurr.fX, click->fCurr.fY);
            this->inval(NULL);
            return true;
            }

    private:
        typedef SampleView INHERITED;
    };

//////////////////////////////////////////////////////////////////////////////

static SkView* MyFactory()
    {
    return new PatchView;
    }
static SkViewRegister reg(MyFactory);

